On desktop, just ctrl+F5 to do a hard refresh. On mobile, let me just copypaste this from discord:
To clear the issue on mobile devices:
- On Chrome, tap on the lock icon in the address bar > Site settings > Clear stored data; if it still doesn't work,
-- Android Chrome: Settings > Privacy > Clear browsing data > clear "Cached images and files"
-- iOS Chrome: Settings > History > Clear history > clear "Cached images and files"
-- Step three: Throw Chrome in the fire for being so goddamn obtuse
- On Firefox, I believe you can long press on the refresh button to do a hard refresh
- On iOS Safari, apparently "settings > safari > advanced > website data > search for mangadex.org > swipe left on the entry > tap delete" > buy android